The cylindrical antenna with gap

The Cylindrical Antenna with Gap

Narrowbeam cylindrical antenna array with sparse antenna spacing

In this paper we suggest a cylindrical array, which utilizes signal cancellation and sparse element spacing. The array has narrow beamwidth and low sidelobe level. The beamwidth is about 12° for a 35 element array having -20 dB sidelobe level. Omnidirectional coverage area is obtained by a combination of commutation and phasing. The array has less elements and smaller size than a respective arr...

Admittance Dependence of the Infinite Cylindrical Antenna Upon Exciting Gap Thickness

The admittance of an infinite cylindrical antenna is calculated as a function of exciting frequency and exciting gap thickness. The results obtained show that an asymptotic analytical expression derived for the susceptance by Chen and Keller and also later by Fante, is strictly valid only in the limit of "Vanishing gap thickness. An altenate analYtical. form is presented-for die susceptance, wh...

Antenna Designs with Electromagnetic Band Gap Structures

The word “meta”, in Greek language, means beyond. It implies that the electromagnetic response of metamaterials (MTMs) is unachievable or unavailable in conventional materials. Many efforts have been done to search for an adequate definition for MTMs. In 2002, J.B. Pendry wrote in a conference paper: “meta-materials, materials whose permeability and permittivity derive from their structure”. La...

Cylindrical/Spherical Near-Field Antenna Measurement System

A low-cost, fully operational cylindrical and spherical near-field antenna measurement system designed, built, and programmed by a University of Rhode Island Capstone team is presented. The goal of this project was to modify an existing planar near-field system and apply new processing techniques to extract the far-field patterns of an antenna under test (AUT) of any physical shape. The aim of ...